The present invention relates to an apparatus including an electrostatic precipitator, which is used for removing contaminants from a heated gas stream and to a related method.
In a number of industrial processes, it is recognized that the gaseous effluent from the processing steps contains unsatisfactorily large amounts of contaminants. For example, in the production of particle board, the product is heated by combustion gases resulting from a wood fire, the effluent gas containing substantial quantities of gaseous hydrocarbon fractions.
In past years, the exhaust gases were simply discharged to atmosphere, without treatment. More recently, several solutions for exhaust treatment have been proposed. One has been to inject additional fresh air into the exhaust gases, to reduce the concentration of the contamination. Since this did not reduce the total amount of contaminants discharged into the atmosphere, this procedure has been found to be unsatisfactory.
In another proposal, effluent gases were passed through passages between relatively cold stones. It was found, however, that while the cold stones removed contaminants by condensing them, the liquid contaminant was then accumulated on the stones, and over time blocked the passages, requiring that the stones be cleansed of the contaminants. This suggestion, also, proved to be unsatisfactory because of the expenses involved in cleaning the accumulated contaminants which had been deposited on the stones, as well as because the process became less efficient as more and more contaminant material was deposited onto the stones, or onto contaminant already in place on the stones.